Interaction between the fission yeast nim1/cdr1 protein kinase and a dynamin-related protein

The nim1/cdr1 protein kinase is required for an efficient adaptation of cel l cycle parameters to changes in nutritional conditions. We have isolated m sp1, a new fission yeast member of the dynamin-related large GTPase family, in a two-hybrid screen designed to identify proteins interacting with the nim1 kinase, Msp1 has been shown to be essential for the maintenance of mtD NA and hence for the inheritance of functional mitochondria. We present evi dence indicating that nim1 and msp1 proteins physically interact both in vi tro and in vivo in fission yeast. These interactions occur through the amin oterminal catalytic domain of nim1 and the carboxy-terminal putative regula tory domain of msp1, These results provide new evidence for the existence o f a connection between mitochondrial function and the cell cycle machinery. (C) 1999 Federation of European Biochemical Societies.